I like to know whats going on, so I did it the hard way...

This config line kills Serout2 functionality.
@ __CONFIG _CONFIG4L, _DEBUG_OFF_4L & _LVP_OFF_4L & _STVREN_OFF_4L

This line restores it.
@ __CONFIG _CONFIG4L, _STVREN_ON_4L & _LVP_OFF_4L & _XINST_OFF_4L

Drilling down to individual config parameters, if I add this one to my original list Serout2 works again.
& _XINST_OFF_4L

The datasheet refers to this as an Extended Instruction set enabling bit. I read a bit about it, and it's use is way beyond my comprehension.

What the ?
And why does it just break the Serout2 command and not everything else in PBP too ?

It's days like these I really wonder why we bothered coming out of caves and inverting the wheel anyway, it would have been much less pain just staying in a nice warm cave